[R] improving a bar graph

[Bob Green]

Hello,

Below is the code for a basic bar graph. I was seeking advice 
regarding the following:

(a)  For each time period there are values from 16 people. How I can 
change the colour value so that each person has a different colour, 
which recurs across each of the three graphs/tie epriods?

(b) I have seen much more sophisticated examples using lattice (e.g 
each person has a separate panel/plot). I am open to alternative code 
as to how I could present this data.

Time1 <- c(9.0,6.0,1.0,5.0,7.0,9.0,5.0,7.5,6.0,8.0,5.0,5.0,9.0,4.0,5.0,5.0)
Time2 <- c (10,5,3,3,3,6,7,8,5,8,7,7,9,8,5,3)
Time3 <- c (10,0,3,0,0,6,0,0,0,0,0,0,0,0,0,0)
df  <- rbind  (Time1, Time2, Time3)
dft <- (t(df))
dft
barplot(dft, beside = TRUE, main= "Risk score by assessment", xlab = 
" Score", ylab = "frequency", col="blue")


Any assistance is much appreciated,

regards

Bob Green